added everything from PR #2

https://github.com/NotHavocc/eggroom-extension/pull/2

tldr; Changed the background so it is no longer cutoff, and the tree moves, changed the music file to remove fadeout.

The buttons have been drastically moved and scaled so button1 (the one you get the egg from) is the tree and button2 ("He is behind the tree.") is fullscreen.